U.S. patent number 11,262,880 [Application Number 17/043,879] was granted by the patent office on 2022-03-01 for high performance film-type touch sensor.
This patent grant is currently assigned to Dongwoo Fine-Chem Co., Ltd.. The grantee listed for this patent is DONGWOO FINE-CHEM CO., LTD.. Invention is credited to Byung Jin Choi, Keon Kim, Jae Hyun Lee, Ju In Yoon.
United States Patent |
11,262,880 |
Lee , et al. |
March 1, 2022 |
High performance film-type touch sensor
Abstract
A high performance touch sensor according to the present
invention comprises: a substrate; a first detection electrode
formed on the substrate; an insulation layer formed on the first
detection electrode; a second detection electrode formed on the
insulation layer; and a protection layer formed on the second
detection electrode, wherein one of the first detection electrode
and the second detection electrode has a triple-film structure
including a metal oxide and a thin film metal laminated on each
other, and the other one includes a metal pattern. Therefore, the
present invention can implement touch sensor having a high
resolution and a large area while simultaneously satisfying a low
resistance characteristic and an optical characteristic, facilitate
progress of a high-temperature process, and diversify the
substrate.
Inventors: |
Lee; Jae Hyun (Uiwang-si,
KR), Yoon; Ju In (Pyeongtaek-si, KR), Kim;
Keon (Gungpo-si, KR), Choi; Byung Jin (Incheon,
KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
DONGWOO FINE-CHEM CO., LTD. |
Iksan-si |
N/A |
KR |
|
|
Assignee: |
Dongwoo Fine-Chem Co., Ltd.
(Jeollabuk-do, KR)
|
Family
ID: |
1000006148327 |
Appl.
No.: |
17/043,879 |
Filed: |
March 29, 2019 |
PCT
Filed: |
March 29, 2019 |
PCT No.: |
PCT/KR2019/003689 |
371(c)(1),(2),(4) Date: |
September 30, 2020 |
PCT
Pub. No.: |
WO2019/190256 |
PCT
Pub. Date: |
October 03, 2019 |
Prior Publication Data
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|
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Document
Identifier |
Publication Date |
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US 20210034199 A1 |
Feb 4, 2021 |
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Foreign Application Priority Data
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|
|
|
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Mar 30, 2018 [KR] |
|
|
10-2018-0037377 |
Mar 28, 2019 [KR] |
|
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10-2019-0035466 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F
3/0445 (20190501); G06V 40/1306 (20220101) |
Current International
Class: |
G06F
3/044 (20060101); G06K 9/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2016-173697 |
|
Sep 2016 |
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JP |
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10-2014-0003728 |
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Jan 2014 |
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KR |
|
101372525 |
|
Mar 2014 |
|
KR |
|
10-2014-0059428 |
|
May 2014 |
|
KR |
|
10-2014-0133401 |
|
Nov 2014 |
|
KR |
|
10-2015-0032150 |
|
Mar 2015 |
|
KR |
|
10-2016-0122291 |
|
Oct 2016 |
|
KR |
|
10-2017-0073186 |
|
Jun 2017 |
|
KR |
|
10-2017-0076340 |
|
Jul 2017 |
|
KR |
|
Other References
First Office Action issued in counterpart Korean Patent Appln. No.
10-2019-0035466 dated May 25, 2020, and its English translation.
cited by applicant .
International Search Report and Written Opinion issued in
counterpart PCT Appln. No. PCT/KR2019/003689 dated Jul. 18, 2019,
and its English translation. cited by applicant.
|
Primary Examiner: Siddiqui; Md Saiful A
Attorney, Agent or Firm: DLA Piper LLP (US)
Claims
What is claimed is:
1. A high performance touch sensor comprising: a substrate; a first
sensing electrode formed on the substrate; an insulating layer
formed on the first sensing electrode; a second sensing electrode
formed on the insulating layer; and a protective layer formed on
the second sensing electrode, wherein one electrode of the first
sensing electrode and the second sensing electrode has a
triple-layered structure in which metal oxide, thin film metal, and
the metal oxide are sequentially stacked, and the other electrode
thereof includes a metal pattern, wherein a line width of the
electrode including the metal pattern among the first sensing
electrode and the second sensing electrode is 1 .mu.m or more and 8
.mu.m or less, wherein a sum of line resistances of electrodes
including the metal pattern having the line width between 1 .mu.m
or more and 8 .mu.m constituting one unit sensing cell among a
plurality of unit sensing cells is 30.2.OMEGA. or more and
90.OMEGA. or less, the plurality of unit sensing cells correspond
to an active region where the first sensing electrode and the
second sensing electrode intersect, wherein a size of a pitch of
one unit sensing cell among the plurality of unit sensing cells is
50 .mu.m or more and 110 .mu.m or less.
2. The high performance touch sensor of claim 1, wherein, in a plan
view of the electrode including the metal pattern among the first
sensing electrode and the second sensing electrode, unit patterns
constituting the metal pattern do not intersect each other.
3. The high performance touch sensor of claim 2, wherein the unit
patterns constituting the metal pattern have a stripe shape.
4. The high performance touch sensor of claim 3, wherein a boundary
surface of the unit patterns having the stripe shape has a curved
shape.
5. The high performance touch sensor of claim 1, further comprising
a pad electrode connected to the electrode including the metal
pattern among the first sensing electrode and the second sensing
electrode.
6. The high performance touch sensor of claim 5, wherein the pad
electrode is made of the same material as the electrode including
the metal pattern among the first sensing electrode and the second
sensing electrode.
7. The high performance touch sensor of claim 5, wherein the
protective layer partially covers the pad electrode.
8. The high performance touch sensor of claim 5, further comprising
a pad protection electrode formed on the pad electrode to protect
the pad electrode.
9. The high performance touch sensor of claim 1, wherein a sheet
resistance of the electrode having the triple-layered structure
among the first sensing electrode and the second sensing electrode
is 3 .OMEGA./sq or more and 10 .OMEGA./sq or less.
10. The high performance touch sensor of claim 1, wherein a light
transmittance of the electrode having the triple-layered structure
among the first sensing electrode and the second sensing electrode
is 80% or more and 93% or less.
11. The high performance touch sensor of claim 1, wherein a light
transmittance of the touch sensor including the substrate, the
first sensing electrode, the insulating layer, the second sensing
electrode, and the protective layer is 80% or more and 90% or
less.
12. The high performance touch sensor of claim 1, wherein the
electrodes including the thin film metal and the metal pattern
include at least one selected from the group consisting of silver
(Ag), copper (Cu), calcium (Ca), nickel (Ni), aluminum (Al),
chromium (Cr), molybdenum (Mo), cobalt (Co), titanium (Ti),
palladium (Pd), indium (In), tungsten (W), cadmium (Cd), and an
alloy thereof.
13. The high performance touch sensor of claim 1, further
comprising a separation layer formed between the substrate and the
first sensing electrode.
14. The high performance touch sensor of claim 13, further
comprising an inner protective layer formed between the separation
layer and the first sensing electrode.
Description
TECHNICAL FIELD
This invention relates to a touch sensor and, more particularly, to
a high performance touch sensor allowing low-resistance
characteristics and optical characteristics to be concurrently
satisfied and also allowing high resolution and a large area to be
implemented.
Background Art
Generally, touch sensors are devices that detect a touch point in
response to a touch when a user touches an image being displayed on
a screen with a finger, a touch pen, or the like. According to
technologies applied to the touch sensors, there are various types
such as a capacitive type, a resistive film type, and a surface
acoustic wave type using an infrared ray or ultrasonic wave.
Such a touch sensor is generally manufactured to have a structure
mounted on a display device such as a liquid crystal display (LCD)
or an organic light-emitting diode (OLED). Recently, research has
been actively conducted on a thinner, lighter, and bendable
film-type touch sensor using a polymer film, which replaces a glass
substrate, as a base film.
Recently, as various functions are integrated in mobile devices,
mobile devices to which a high resolution touch sensor is applied
are gradually expanding. In particular, an application, which
recognizes a user's fingerprint through the high resolution touch
sensor and thus is applied to various security signatures, is being
developed.
Meanwhile, in order for a touch sensor to perform a fingerprint
recognition function, a pitch of a unit sensing cell constituting
the touch sensor should be miniaturized sufficiently to detect a
change in capacitance between a ridge and a valley of a user's
fingerprint having a fine interval. In this case, in a process of
miniaturizing the unit sensing cell, product defects may be caused,
and since the pitch of the cell is narrowed in response to a
resolution of the touch sensor and the number of channels is
increased, an increase in resistance is inevitable.
RELATED ART DOCUMENTS
Patent Document
Korean Registered Patent Publication No. 10-1372525 (Registration
Date: Mar. 4, 2014, Title: Method of manufacturing touch screen
panel using photosensitive metal nanowire)
SUMMARY OF INVENTION
Technical Problem
A technical objective of the present invention is to provide a high
performance touch sensor allowing low-resistance characteristics
and optical characteristics to be concurrently satisfied and also
allowing high resolution and a large area to be implemented.
Another technical objective of the present invention is to provide
a high performance touch sensor, in which a pitch of a unit sensing
cell constituting a touch sensor may be miniaturized sufficiently
to detect a change in capacitance between a ridge and a valley of a
user's fingerprint, an increase in resistance may also be
suppressed to secure low-resistance characteristics, and
concurrently, optical characteristics including light transmittance
may be improved.
Solution to Problem
A high performance touch sensor according to the present invention
includes a substrate, a first sensing electrode formed on the
substrate, an insulating layer formed on the first sensing
electrode, a second sensing electrode formed on the insulating
layer, and a protective layer formed on the second sensing
electrode, wherein one electrode of the first sensing electrode and
the second sensing electrode has a triple-layered structure
including a stacked metal oxide and a thin film metal, and the
other electrode thereof includes a metal pattern.
The high performance touch sensor according to the present
invention is characterized in that, in a plan view of the electrode
including the metal pattern among the first sensing electrode and
the second sensing electrode, unit patterns constituting the metal
pattern may not intersect each other.
The high performance touch sensor according to the present
invention is characterized in that the unit patterns constituting
the metal pattern may have a stripe shape.
The high performance touch sensor according to the present
invention is characterized in that a boundary surface of the unit
patterns having the stripe shape may have a curved shape.
The high performance touch sensor according to the present may
further include a pad electrode connected to the electrode
including the metal pattern among the first sensing electrode and
the second sensing electrode.
The high performance touch sensor according to the present
invention is characterized in that the pad electrode may be made of
the same material as the electrode including the metal pattern
among the first sensing electrode and the second sensing
electrode.
The high performance touch sensor according to the present
invention is characterized in that the protective layer may
partially cover the pad electrode.
The high performance touch sensor according to the present
invention may further include a pad protection electrode formed on
the pad electrode to protect the pad electrode.
The high performance touch sensor according to the present
invention is characterized in that the electrode having the
triple-layered structure among the first sensing electrode and the
second sensing electrode may have a structure in which the metal
oxide, the thin film metal, and the metal oxide are sequentially
stacked.
The high performance touch sensor according to the present
invention is characterized in that a line width of the electrode
including the metal pattern among the first sensing electrode and
the second sensing electrode may be 1 .mu.m or more and 8 .mu.m or
less.
The high performance touch sensor according to the present
invention is characterized in that a sheet resistance of the
electrode having the triple-layered structure among the first
sensing electrode and the second sensing electrode may be 3
.OMEGA./sq or more and 10 .OMEGA./sp or less.
The high performance touch sensor according to the present
invention is characterized in that a light transmittance of the
electrode having the triple-layered structure among the first
sensing electrode and the second sensing electrode may be 80% or
more and 93% or less.
The high performance touch sensor according to the present
invention is characterized in that a light transmittance of the
touch sensor including the substrate, the first sensing electrode,
the insulating layer, the second sensing electrode, and the
protective layer may be 80% or more and 90% or less.
The high performance touch sensor according to the present
invention is characterized in that a sum of line resistances of
electrodes constituting one unit sensing cell among a plurality of
unit sensing cells that correspond to a cross region between the
first sensing electrode and the second sensing electrode may be
13.OMEGA. or more and 90.OMEGA. or less.
The high performance touch sensor according to the present
invention is characterized in that the electrodes including the
thin film metal and the metal pattern may include at least one
selected from the group consisting of silver (Ag), copper (Cu),
calcium (Ca), nickel (Ni), aluminum (Al), chromium (Cr), molybdenum
(Mo), cobalt (Co), titanium (Ti), palladium (Pd), indium (In),
tungsten (W), cadmium (Cd), and an alloy thereof.
The high performance touch sensor according to the present
invention may further include a separation layer formed between the
substrate and the first sensing electrode.
The high performance touch sensor according to the present
invention may further include an inner protective layer formed
between the separation layer and the first sensing electrode.
The high performance touch sensor according to the present
invention is characterized in that a size of a pitch of one unit
sensing cell among a plurality of unit sensing cells that
correspond to a cross region between the first sensing electrode
and the second sensing electrode may be 50 .mu.m or more and 110
.mu.m or less.
Advantageous Effects of Invention
According to the present invention, there is an effect of providing
a high performance touch sensor allowing low-resistance
characteristics and optical characteristics to be concurrently
satisfied and also allowing high resolution and a large area to be
implemented, and a method of manufacturing the same.
In addition, there is an effect of providing a high performance
touch sensor and a method of manufacturing the same, in which a
pitch of a unit sensing cell constituting a touch sensor can be
miniaturized sufficiently to detect a change in capacitance between
a ridge and a valley of a user's fingerprint, an increase in
resistance can also be suppressed to secure low-resistance
characteristics, and concurrently, optical characteristics
including light transmittance can be improved.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a view illustrating a high performance touch sensor
according to a first embodiment of the present invention.
FIG. 2 is a view illustrating a high performance touch sensor
according to a second embodiment of the present invention.
FIG. 3 is a view illustrating a high performance touch sensor
according to a third embodiment of the present invention.
FIG. 4 is a view illustrating one exemplary shape of unit patterns
constituting a metal pattern according to one embodiment of the
present invention.
FIG. 5 is a view illustrating another exemplary shape of unit
patterns constituting a metal pattern according to one embodiment
of the present invention.
DETAILED DESCRIPTION OF EMBODIMENT
Since specific structural or functional descriptions for
embodiments according to the concept of the invention disclosed
herein are merely exemplified for purposes of describing the
embodiments according to the concept of the invention, the
embodiments according to the concept of the invention may be
embodied in various forms but are not limited to the embodiments
described herein.
While the embodiments of the present invention are susceptible to
various modifications and alternative forms, specific embodiments
thereof are shown by way of example in the accompanying drawings
and will herein be described in detail. It should be understood,
however, that there is no intent to limit the invention to the
particular forms disclosed, but on the contrary, the invention is
to cover all modifications, equivalents, and alternatives falling
within the spirit and scope of the invention.
It will be understood that, although the terms "first," "second,"
etc. may be used herein to describe various elements, these
elements should not be limited by these terms. These terms are only
used to distinguish one element from another element. For example,
a first element could be termed a second element, and similarly, a
second element could be termed a first element, without departing
from the scope of the present invention.
It will be understood that when an element is referred to as being
"connected" or "coupled" to another element, it can be directly
connected or coupled to another element or intervening elements may
be present. In contrast, when an element is referred to as being
"directly connected" or "directly coupled" to another element,
there are no intervening elements present. Other words used to
describe the relationship between elements should be interpreted in
a like fashion (i.e., "between" versus "directly between,"
"adjacent" versus "directly adjacent," etc.).
The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting to
the invention. A single form of expression is meant to include
multiple elements unless otherwise stated. It will be further
understood that the terms "comprises," "comprising," "includes,"
and/or "including," when used herein, specify the presence of
stated features, integers, steps, operations, elements, and/or
components, but do not preclude the presence or addition of one or
more other features, integers, steps, operations, elements,
components, and/or groups thereof.
Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
invention belongs. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and will not be
interpreted in an idealized or overly formal detect unless
expressly so defined herein.
Hereinafter, exemplary embodiments of the present invention will be
described in detail with reference to the accompanying
drawings.
FIG. 1 is a view illustrating a high performance touch sensor
according to a first embodiment of the present invention. FIG. 2 is
a view illustrating a high performance touch sensor according to a
second embodiment of the present invention. FIG. 3 is a view
illustrating a high performance touch sensor according to a third
embodiment of the present invention. As will be described below,
the first and second embodiments have a structure in which an
electrode having a triple-layered structure is positioned at a
lower side, and conversely, the third embodiment has a structure in
which an electrode having a triple-layered structure is positioned
at an upper side.
Referring to FIG. 1, the high performance touch sensor according to
the first embodiment of the present invention includes a substrate
10, a separation layer 12, an inner protective layer 14, a first
sensing electrode 20, an insulating layer 30, a second sensing
electrode 40, a pad electrode 45, a protective layer 50, and a pad
protection electrode 60.
First, regions such as an active region AR, a junction region JR, a
trace region TR, and a pad region PR, which functionally partition
the high performance touch sensor according to the embodiments of
the present invention, will be defined.
The active region AR is a region in which an image provided by a
device coupled to the touch sensor is displayed as well as being a
region in which a touch signal input from a user is detected. The
active region AR is provided with a plurality of sensing electrode
patterns formed in directions intersecting each other. Hereinafter,
as will be described in detail, for example, the sensing electrode
patterns constituting the touch sensor may include the first
sensing electrode 20 and the second sensing electrode 40 which are
formed to intersect each other in a state of being insulated from
each other by the insulating layer 30.
The pad region PR is provided with bonding pad patterns to which a
flexible printed circuit (FPC), which transmits a touch signal
detected by the sensing electrode patterns provided in the active
region AR to a driver (not shown), is connected.
The junction region JR and the trace region TR are provided with
lines which electrically connect the sensing electrode patterns
provided in the active region AR and the bonding pad patterns
provided in the pad region PR.
The substrate 10 serves to structurally support the components of
the high performance touch sensor according to the first embodiment
of the present invention.
For example, the substrate 10 may include a rigid material having
high heat resistance and chemical resistance, such as glass or
stainless steel (SUS), or may include a flexible material having
excellent flexible properties.
As a more specific example, the substrate 10 may be implemented in
the form of a base film made of any material having excellent
flexible and light transmission properties.
For example, the base film may be a transparent optical film or a
polarizing plate.
For example, a film having excellent transparency, mechanical
strength, and thermal stability may be used as the transparent
optical film. A specific example of the transparent optical film
may include a film made of at least one selected from thermoplastic
resins including a polyester-based resin such as polyethylene
terephthalate, polyethylene isophthalate, polyethylene naphthalate,
or polybutylene terephthalate, a cellulose-based resin such as
diacetyl cellulose or triacetyl cellulose, a polycarbonate-based
resin, an acrylic-based resin such as polymethyl(meth)acrylate or
polyethyl(meth)acrylate, a styrene-based resin such as polystyrene
or an acrylonitrile-styrene copolymer, a polyolefin-based resin
such as polyethylene, cyclic-based polyolefin, polyolefin having a
norbornene structure, or an ethylene-propylene copolymer, a vinyl
chloride-based resin, an amide-based resin such as nylon or
aromatic polyamide, an imide-based resin, a polyethersulfone-based
resin, a sulfone-based resin, a polyether ether ketone-based resin,
a polyphenylene sulfide-based resin, a vinyl alcohol-based resin, a
vinylidene chloride-based resin, a vinyl butyral-based resin, an
allylate-based resin, a polyoxymethylene-based resin, and an
epoxy-based resin. In addition, a film made of a blend of the
above-described thermoplastic resins may be used. Furthermore, a
film made of a thermosetting resin based on (meth)acrylate,
urethane, acrylic urethane, epoxy, or silicone, or an ultraviolet
(UV)-curable resin may also be used. A thickness of the
above-described transparent optical film may be appropriately
determined but may be generally determined to be in a range of 1
.mu.m to 500 .mu.m in consideration of strength, workability such
as handleability, thin layer formability, or the like. In
particular, the thickness of the transparent optical film is
preferably in a range 1 .mu.m to 300 .mu.m and, more preferably, in
a range of 5 .mu.m to 200 .mu.m.
The transparent optical film may include one or more appropriate
additives. Examples of the additives may include an UV absorber, an
antioxidant, a lubricant, a plasticizer, a release agent, a
coloration preventing agent, a flame retardant, a nucleating agent,
an antistatic agent, a pigment, a coloring agent, and the like. The
transparent optical film may have a structure including various
functional layers such as a hard coating layer, an antireflection
layer, and a gas barrier layer on one or both sides of a film. The
functional layers are not limited to the above-described layers,
and various functional layers may be used according to use
thereof.
In addition, if necessary, the transparent optical film may be
surface-treated. Examples of such surface treatment may include dry
treatment such as plasma treatment, corona treatment, or primer
treatment, and chemical treatment such as alkali treatment
including saponification treatment.
In addition, the transparent optical film may be an isotropic film,
a retardation film, or a protective film.
When the transparent optical film is the isotropic film, an
in-plane retardation (Ro) is 40 nm or less and, preferably, 15 nm
or less (wherein Ro=[nx-ny].times.d], nx and ny refer to a main
refractive index in a film plane, and d refers to a film
thickness), and a retardation (Rth) in a thickness direction is in
a range of -90 nm to +75 nm, preferably, in a range of -80 nm to
+60 nm and, particularly, in a range of -70 nm to +45 nm (wherein
Rth=[(nx+ny)/2-nz].times.d), nx and ny refer to a main refractive
index in a film plane, and nz refers to a refractive index in the
thickness direction of the film, andd refers to a film
thickness.
The retardation film may be a film manufactured through a method of
uniaxially or biaxially stretching a polymer film, applying a
polymer, or applying a liquid crystal. The retardation film may be
used for improvement or control of optical characteristics, such as
viewing angle compensation, color sensitivity improvement, light
leakage prevention, or color aesthetic control of a display. Types
of the retardation film include a half-wave or quarter-wave plate,
a positive C-plate, a negative C-plate, a positive A-plate, a
negative A-plate, and a biaxial plate.
The protective film may be a polymer resin film including an
adhesive layer on at least one surface thereof or a self-adhesive
film made of polypropylene. The protective film may be used for
protection of a surface of the touch sensor and improvement of
processibility.
The polarizing plate may be any one known to be used in a display
panel. Specifically, the polarizing plate may be formed by
installing the protective layer 50 on at least one surface of a
polarizer obtained by stretching a polyvinyl alcohol film and
dyeing the stretched polyvinyl alcohol film with iodine or a
dichroic pigment, by orienting a liquid crystal to provide
performance of a polarizer thereto, or by applying an oriented
resin such as polyvinyl alcohol on a transparent film and
stretching and dyeing the transparent film, but the present
invention is not limited thereto.
When the substrate 10 is implemented as a film formed of a flexible
material, in a state in which components including the first
sensing electrode 20 and the second sensing electrode 40 are formed
on a rigid carrier substrate made of glass, SUS, or the like during
a manufacturing process, the separation layer 12 and the inner
protective layer 14 formed between the substrate 10 and the first
sensing electrode 20 performs a function of separating the
components from the carrier substrate. Additionally, the inner
protective layer 14 formed on the separation layer 12 also performs
a function of protecting the separation layer 12 in a process of
depositing and etching the first sensing electrode 20, the second
sensing electrode 40, and the like.
The first sensing electrode 20 formed in the active region AR of
the substrate 10 performs a sensing electrode function of sensing a
touch signal of a user together with the second sensing electrode
40 to be described below.
Meanwhile, as described in description of the problems of the
related art, in order for a touch sensor to perform a fingerprint
recognition function, a pitch of a unit sensing cell constituting
the touch sensor should be miniaturized sufficiently to detect a
change in capacitance between a ridge and a valley of a user's
fingerprint having a fine interval. In this case, in a process of
miniaturizing the unit sensing cell, product defects may be caused,
and since the pitch of the cell is narrowed in response to a
resolution of the touch sensor and the number of channels is
increased, an increase in resistance is inevitable.
However, according to the first embodiment of the present
invention, a pitch of a unit sensing cell constituting the touch
sensor can be miniaturized sufficiently to detect a change in
capacitance between a ridge and a valley of a user's fingerprint,
an increase in resistance can also be suppressed to secure
low-resistance characteristics, and concurrently, optical
characteristics including light transmittance can be improved.
Hereinafter, a main technical configuration applied to the first
embodiment of the present invention to concurrently achieve the
technical objects of securing low-resistance characteristics and
improving optical characteristics of the touch sensor will be
described.
In the first embodiment of the present invention, the first sensing
electrode 20 formed on the substrate 10 may have a triple-layered
structure including a stacked metal oxide and thin film metal, and
the second sensing electrode 40 may include a metal pattern.
In the first embodiment of the present invention, such
configurations applied to the first sensing electrode 20 and the
second sensing electrode 40 overcome a contradictory relationship
between resistance characteristics and optical characteristics and
convert the contradictory relationship into a complementary
relationship, thereby providing a touch sensor capable of
concurrently acquiring low-resistance characteristics and excellent
optical characteristics.
This will be described in more detail as follows.
In the first sensing electrode 20 formed to have the triple-layered
structure, low-resistance characteristics are relatively lowered,
but optical characteristics including light transmittance are
excellent as compared with another electrode, that is, the second
sensing electrode 40 including the metal pattern.
On the other hand, in the second sensing electrode 40 including the
metal pattern, since resistance is lower as compared with another
electrode, that is, the first sensing electrode 20 formed to have
the triple-layered structure, low-resistance characteristics are
relatively improved, but optical characteristics including light
transmittance (for example, visibility and haze) are lowered.
Accordingly, when the first sensing electrode 20 is formed to have
the triple-layered structure including the stacked metal oxide and
thin film metal and the second sensing electrode 40 is formed to
include the metal pattern, since the first sensing electrode 20 and
the second sensing electrode 40 have a complementary relationship
in view of low-resistance characteristics and optical
characteristics, it is possible to provide a high performance touch
sensor having low-resistance characteristics and excellent optical
characteristics.
For example, the first sensing electrode 20 having the
triple-layered structure may be formed to have a triple-layered
structure in which a metal oxide, a thin film metal, and a metal
oxide are sequentially stacked.
For example, in a plan view of the second sensing electrode 40
including the metal pattern, unit patterns constituting the metal
pattern may be formed so as to not intersect each other differently
from a known metal mesh. That is, the unit patterns constituting
the metal pattern may be formed to not intersect each other in the
active region AR but may be formed to intersect each other in the
junction region JR positioned outside the active region AR. When
the unit patterns are formed as described above, a light
transmittance of the second sensing electrode 40 including the
metal pattern can be increased as compared with a known metal mesh
pattern.
FIGS. 4 and 5 are views illustrating exemplary shapes of unit
patterns constituting a metal pattern according to one embodiment
of the present invention.
For example, referring additionally to FIGS. 4 and 5, the unit
patterns constituting the metal pattern may be formed to have a
stripe shape, and the stripe shape may include a straight line or a
curved line. As shown in FIG. 5, the stripe shape including the
curved line means that a boundary surface of the unit patterns
having the stripe shape has a curved shape. As described above,
when the unit patterns constituting the metal pattern are formed to
have the stripe shape, as compared with a conventional metal mesh
pattern, the occurrence of a moire is small and a haze is minor so
that optical characteristics are improved.
For example, a line width of the second sensing electrode 40
including the metal pattern may be 1 .mu.m or more and 8 .mu.m or
less. When the line width is 1 .mu.m or more and 8 .mu.m or less,
low-resistance characteristics and excellent optical
characteristics can be concurrently secured. When the line width is
less than 1 optical characteristics including light transmittance
are improved, but resistance is increased, which makes it difficult
to secure low-resistance characteristics. When the line width
exceeds 8 .mu.m, resistance is decreased, which is advantageous for
securing low-resistance characteristics, but light transmittance is
lowered, which lowers optical characteristics. In terms of
concurrently securing low-resistance characteristics and excellent
optical characteristics, it is more preferable that the line width
is 1 .mu.m or more and 3.5 .mu.m or less.
Experimental data for demonstrating such a critical significance
are disclosed in Tables 1 and 2 below.
Table 1 shows experimental data according to a related art, and
when both of two electrodes are electrodes including a metal
pattern, Table 1 shows experimental data about resistance
characteristics and optical characteristics according to a line
width of the electrode. Table 2 shows experimental data according
to one embodiment of the present invention, and when one of the
first sensing electrode 20 and the second sensing electrode 40 has
a triple-layered structure including a stacked metal oxide and thin
film metal and the other thereof is an electrode including a metal
pattern, Table 2 shows experimental data about resistance
characteristics and optical characteristics according to a line
width of the electrode including the metal pattern.
TABLE-US-00001 TABLE 1 Line width (.mu.m) 15 12 10 8 7 5 3.5 2.5 2
1.5 1 0.7 Resistance (.OMEGA.) 1.7 2.1 2.5 3.2 3.6 5.0 7.2 10.1
12.6 16.8 25.2 36.0 Transmittance (%) 66.8 68.2 69.9 72.1 74.4 77.7
78.1 79.7 80.1 80.9 81.2 82.1 Visibility x x x x x x x .DELTA.
.DELTA. .DELTA. .smallcircle. .smallcircl- e. Haze 19.0 17.0 14.0
12.1 10.9 9.2 7.9 6.5 5.8 4.3 3.1 2.2
TABLE-US-00002 TABLE 2 Line width (.mu.m) 15 12 10 8 7 5 3.5 2.5 2
1.5 1 0.7 Resistance (.OMEGA.) 13.14 20.08 24.30 30.2 36.6 43.0
50.2 56.3 65.2 78.2 - 90.0 110.3 Transmittance (%) 75.0 76.5 78.3
80.7 81.5 82.1 83.4 84.5 86.8 88.1 90.0 90.5 Visibility x x x
.DELTA. .DELTA. .DELTA. .smallcircle. .smallcircle. .smal- lcircle.
.smallcircle. .smallcircle. .smallcircle. Haze 8.0 5.6 4.3 3.2 2.5
1.5 1.0 0.8 0.4 0.3 0.2 0.2
In an experiment above, resistance is the sum of line resistances
of electrodes constituting one unit sensing cell among a plurality
of unit sensing cells that correspond to a cross region between the
first sensing electrode 20 and the second sensing electrode 40 and
has a value obtained using K-9510AT (manufactured by MIK21
Company), transmittance has a value obtained using Konica-Minolta
CM-3300D, visibility is a result evaluated based on the number of
people who feel that a pattern is visibly recognizable in an
experimental group of 100 people, .largecircle. refers to when five
people or less recognize a pattern, .DELTA. refers to when six
people or more and ten people or less recognize a pattern, x refers
to when ten people or more recognize a pattern, and a haze has a
value obtained using Haze-Meter (HM-150).
For example, a sheet resistance of the first sensing electrode 20
having the triple-layered structure may be 3 .OMEGA./sq or more and
10 .OMEGA./sq or less, and a light transmittance thereof may be 80%
or more and 93% or less. When the sheet resistance of the first
sensing electrode 20 having the triple-layered structure is 3
.OMEGA./sq or more and 10 .OMEGA./sq or less and the light
transmittance thereof is 80% or more and 93% or less, it is
possible to secure high light transmittance, which is an advantage
of an electrode having a triple-layered structure, and concurrently
minimize a decrease in low-resistance characteristics due to an
increase in resistance. When the sheet resistance is less than 3
.OMEGA./sq, a thin film metal of a triple layer becomes thick, and
thus, visibility becomes lower. When the sheet resistance exceeds
10 .OMEGA./sq, a high performance touch sensor is not smoothly
driven. In addition, when the light transmittance is less than 80%,
visibility becomes lower, and when the light transmittance exceeds
93%, a thin film metal of a triple layer becomes thick, and thus,
an increase in resistance is inevitable.
For example, in order to secure optical characteristics of the
touch sensor, it is preferable that a light transmittance of the
touch sensor including the substrate 10, the first sensing
electrode 20, the insulating layer 30, the second sensing electrode
40, and the protective layer 50 is 80% or more and 90% or less.
In addition, in order to secure electrical driving characteristics
including, for example, a response speed of the touch sensor, it is
preferable that the sum of the line resistances of the electrodes
constituting one unit sensing cell among the plurality of unit
sensing cells that correspond to the cross region between the first
sensing electrode 20 and the second sensing electrode 40 is
13.OMEGA. or more and 90.OMEGA. or less.
Furthermore, for example, in order to stably recognize a user's
fingerprint without errors, it is preferable that a size of a pitch
of one unit sensing cell among the plurality of unit sensing cells
that correspond to the cross region between the first sensing
electrode 20 and the second sensing electrode 40 is 50 .mu.m or
more and 110 .mu.m or less.
As described above, when the light transmittance of the touch
sensor is set to be 80% or more and 90% or less, the sum of the
line resistances of the electrodes constituting one unit sensing
cell among the plurality of unit sensing cells that correspond to
the cross region between the first sensing electrode 20 and the
second sensing electrode 40 is set to be 13.OMEGA. or more and
90.OMEGA. or less, and the size of the pitch of one unit sensing
cell among the plurality of unit sensing cells that correspond to
the cross region between the first sensing electrode 20 and the
second sensing electrode 40 is 50 .mu.m or more and 110 .mu.m or
less, the pitch of the unit sensing cell constituting the touch
sensor can be miniaturized sufficiently to detect a change in
capacitance between a ridge and a valley of a user's fingerprint,
an increase in resistance can also be suppressed to secure
low-resistance characteristics, and concurrently, optical
characteristics including light transmittance can be improved.
In order to help understand the structure and function of the touch
sensor, more specific configurations of the first sensing electrode
20 and the second sensing electrode 40 will be exemplarily
described as follows.
For example, sensing patterns constituting the first sensing
electrode 20 and the second sensing electrode 40 may be formed to
have an appropriate shape according to the needs of an electronic
device to which the sensing patterns are applied. For example, when
the sensing patterns are applied to a touch screen panel, the
sensing patterns may be formed as two types of patterns such as a
pattern for sensing an x-coordinate and a pattern for sensing a
y-coordinate, but the present invention is not limited thereto.
For example, the first sensing electrode 20 may be formed in a
first direction, the second sensing electrode 40 may be formed in a
second direction, and the second direction intersects the first
direction. For example, when the first direction is an X-direction,
the second direction may be a Y-direction. The first sensing
electrode 20 and the second sensing electrode 40 are electrically
insulated from each other by the insulating layer 30 to be
described below. For example, a metal oxide may include at least
one selected from the group consisting of indium tin oxide (ITO),
indium zinc oxide (IZO), indium zinc tin oxide (IZTO), aluminum
zinc oxide (AZO), zinc oxide (ZnO.sub.x), indium oxide (InO.sub.x),
tin oxide (SnO.sub.x), cadmium tin oxide (CTO), gallium-doped zinc
oxide (GZO), zinc tin oxide (ZTO), and indium gallium oxide (IGO).
Electrodes including a thin film metal and a metal pattern may
include one selected from the group consisting of silver (Ag),
copper (Cu), calcium (Ca), nickel (Ni), aluminum (Al), chromium
(Cr), molybdenum (Mo), cobalt (Co), titanium (Ti), palladium (Pd),
indium (In), tungsten (W), cadmium (Cd), and an alloy thereof, but
the present invention is not limited thereto.
The thickness of the first sensing electrode 20 and the second
sensing electrode 40 is not particularly limited, but in
consideration of the flexibility and excellent resistance
characteristics of the touch sensor, it is preferable that the
thickness is in a range of 300 .ANG. to 2,800 .ANG..
A lower junction portion 23 formed in the junction region JR may be
made of the same material as the first sensing electrode 20 and may
be formed together with the first sensing electrode 20 in a process
of forming the first sensing electrode 20.
The insulating layer 30 is formed in a region including the first
sensing electrode 20 and electrically insulates the first sensing
electrode 20 from the second sensing electrode 40. For example, the
insulating layer 30 may be formed to completely cover the first
sensing electrode 20 and may be formed such that the lower junction
portion 23 is partially exposed through a contact hole. In a
process of forming the insulating layer 30, an insulating pattern
35 may be formed in a portion of the pad region PR in which the pad
electrode 45 is formed.
As a material of the insulating layer 30 that insulates the first
sensing electrode 20 from the second sensing electrode 40, an
insulating material known in the art including an organic material
and an inorganic material may be used without limitation, and for
example, a metal oxide such as silicon oxide, a photosensitive
resin composition including an acrylic-based resin, or a
thermosetting resin composition may be used. Alternatively, the
insulating layer 30 may be formed using an inorganic material such
as silicon oxide (SiO.sub.x) and, in this case, may be formed
through a method such as a deposition method or a sputtering
method.
The second sensing electrode 40 is formed to be opposite to the
first sensing electrode 20 in the active region AR of the
insulating layer 30 and includes a metal pattern.
For example, in a process of forming the second sensing electrode
40, an upper junction portion 43 that is electrically connected to
the lower junction portion 23 may be formed in the junction region
JR, a trace portion 44 may be formed in the trace region TR, and
the pad electrode 45 covering the insulating pattern 35 may be
formed in the pad region PR. The upper junction portion 43, the
trace portion 44, and the pad electrode 45 may be made of the same
material as the second sensing electrode 40.
The protective layer 50 is formed on the insulating layer 30, on
which the second sensing electrode 40 and the upper junction
portion 43 are formed, the trace portion 44, and the pad electrode
45 such that at least a portion of the pad electrode 45 is exposed
through a contact hole or the like.
For example, the protective layer 50 may be made of an insulating
material and may be formed to completely cover the second sensing
electrode 40 positioned in the active region AR, the upper junction
portion 43 positioned in the junction region JR, and the trace
portion 44 positioned in the trace region TR. In addition, the
protective layer 50 may be formed such that the pad electrode 45
positioned in the pad region PR is partially or entirely exposed,
thereby insulating and protecting internal components from the
outside.
As a material of the protective layer 50, an insulating material
known in the art may be used without limitation, and for example, a
metal oxide such as silicon oxide, a photosensitive resin
composition including an acrylic-based resin, or a thermosetting
resin composition may be used. Alternatively, the protective layer
50 may be formed using an inorganic material such as silicon oxide
(SiOx) and, in this case, may be formed through a method such as a
deposition method or a sputtering method.
The pad protection electrode 60 is formed on at least a portion of
the pad electrode 45 to perform a function of preventing a
corrosion phenomenon of the pad electrode 45 caused by moisture or
the like introduced from the outside.
For example, the pad protection electrode 60 may include at least
one selected from the group consisting of ITO, IZO, IZTO, AZO,
ZnO.sub.x, InO.sub.x, SnO.sub.x, CTO, GZO, ZTO, and IGO, but the
present invention is not limited thereto.
As in the first embodiment described in detail above, in the high
performance touch sensor according to the second embodiment of the
present invention shown in FIG. 2, since a first sensing electrode
20 has a triple-layered structure including a stacked metal oxide
and thin film metal and a second sensing electrode 40 has a
configuration including a metal pattern, the descriptions of the
first embodiment may also be applied to the second embodiment in
substantially the same manner.
However, the second embodiment differs from the first embodiment in
a shape of an insulating layer 30. That is, according to the second
embodiment, the insulating layer 30 is formed in a region including
the first sensing electrode 20 and electrically insulates the first
sensing electrode 20 from the second sensing electrode 40. For
example, the insulating layer 30 partially exposes a lower junction
portion 23 formed in a junction region JR through a contact hole
and is stacked on entire surfaces of the first sensing electrode 20
and a substrate 10. Accordingly, a trace portion 44 and a pad
electrode 45 are positioned on the insulating layer 30.
FIG. 3 is a view illustrating the high performance touch sensor
according to the third embodiment of the present invention.
Referring to FIG. 3, as opposed to the first and second
embodiments, the high performance touch sensor according to the
third embodiment of the present invention has a structure in which
an electrode having a triple-layered structure is positioned at an
upper side. That is, according to the third embodiment, a first
sensing electrode 20 formed on a substrate 10 includes a metal
pattern, and a second sensing electrode 40 formed on an insulating
layer 30 has a triple-layered structure including a stacked metal
oxide and thin film metal.
In the third embodiment of the present invention, such
configurations applied to the first sensing electrode 20 and the
second sensing electrode 40 overcome a contradictory relationship
between resistance characteristics and optical characteristics and
convert the contradictory relationship into a complementary
relationship, thereby providing a touch sensor capable of
concurrently acquiring low-resistance characteristics and excellent
optical characteristics.
This will be described in more detail as follows.
In the first sensing electrode 20 including the metal pattern,
optical characteristics including light transmittance are
relatively lowered, but low-resistance characteristics are
excellent as compared with another electrode, that is, the second
sensing electrode 40 formed to have the triple-layered
structure.
On the other hand, in the second sensing electrode 40 having the
triple-layered structure, optical characteristics including light
transmittance are excellent, but low-resistance characteristics are
relatively lowered as compared with another electrode, that is, the
first sensing electrode 20 including the metal pattern.
Accordingly, when the first sensing electrode 20 is formed to
include the metal pattern and the second sensing electrode 40 is
formed to have the triple-layered structure including the stacked
metal oxide and thin film metal, since the first sensing electrode
20 and the second sensing electrode 40 have a complementary
relationship in view of low-resistance characteristics and optical
characteristics, a high performance touch sensor having
low-resistance characteristics and excellent optical
characteristics is provided.
For example, the second sensing electrode 40 having the
triple-layered structure may be formed to have a triple-layered
structure in which a metal oxide, a thin film metal, and a metal
oxide are sequentially stacked.
For example, a line width of the first sensing electrode 20
including the metal pattern may be 1 .mu.m or more and 8 .mu.m or
less. When the line width is 1 .mu.m or more and 8 .mu.m or less,
low-resistance characteristics and excellent optical
characteristics can be concurrently secured. When the line width is
less than 1 optical characteristics including light transmittance
are improved, but resistance is increased, which makes it difficult
to secure low-resistance characteristics. When the line width
exceeds 8 .mu.m, resistance is decreased, which is advantageous for
securing low-resistance characteristics, but light transmittance is
lowered, which lowers optical characteristics.
For example, a sheet resistance of the thin film metal applied to
the second sensing electrode 40 having the triple-layered structure
may be 3 .OMEGA./sq or more and 10 .OMEGA./sq or less, and a light
transmittance thereof may be 80% or more and 93% or less. When the
sheet resistance of the thin film metal is 3 .OMEGA./sq or more and
10 .OMEGA./sq or less and the light transmittance thereof is 80% or
more and 93% or less, it is possible to secure high light
transmittance which is an advantage of an electrode having a
triple-layered structure and concurrently minimize a decrease in
low-resistance characteristics due to an increase in
resistance.
For example, in a process of forming the first sensing electrode
20, a lower junction portion 23 may be formed in a junction region
JR, a trace portion 24 may be formed in a trace region TR, and a
pad electrode 25 may be formed in a pad region PR. The lower
junction portion 23, the trace portion 24, and the pad electrode 25
may be made of the same material as the first sensing electrode
20.
An insulating layer 30 is stacked such that at least a portion of
the lower junction portion 23 and at least a portion of the pad
electrode 25 are exposed through contact holes. The second sensing
electrode 40 is formed to have a structure opposite to the first
sensing electrode 20 with the insulating layer interposed
therebetween.
For example, in a process of forming the second sensing electrode
40, an upper junction portion 43 to be electrically connected to
the lower junction portion 23 may be formed in the junction region
JR, and an intermediate conductor pattern 46 to be electrically
connected to the pad electrode 25 may be formed in the pad region
PR. The upper junction portion 43 and the intermediate conductor
pattern 46 may be made of the same material as the second sensing
electrode 40.
For example, the protective layer 50 may be made of an insulating
material and may be formed to completely cover the second sensing
electrode 40 positioned in an active region AR and the upper
junction portion 43 positioned in the junction region JR. In
addition, the protective layer 50 may be formed such that the
intermediate conductor pattern 46 electrically connected to the pad
electrode 25 positioned in the pad region PR is partially or
entirely exposed, thereby insulating and protecting internal
components from the outside.
A pad protection electrode 60 is formed on at least a portion of
the intermediate conductor pattern 46 electrically connected to the
pad electrode 25 to perform a function of preventing a corrosion
phenomenon of the pad electrode 25 caused by moisture or the like
introduced from the outside.
Excluding such differences, since the third embodiment has
substantially the same technical features as the first and second
embodiments, the descriptions of the first and second embodiments
may also be applied to the third embodiment in substantially the
same manner.
As described above, according to the present invention, there is an
effect of providing a high performance touch sensor capable of
concurrently satisfying low-resistance characteristics and optical
characteristics and also allowing high resolution and a large area
to be implemented.
In addition, there is an effect of providing a high performance
touch sensor in which a pitch of a unit sensing cell constituting a
touch sensor can be miniaturized sufficiently to detect a change in
capacitance between a ridge and a valley of a user's fingerprint,
an increase in resistance can also be suppressed to secure
low-resistance characteristics, and concurrently, optical
characteristics including light transmittance can be improved.
DESCRIPTIONS OF REFERENCE NUMERALS
AR: active region JR: junction region TR: trace region PR: pad
region 10: substrate 12: separation layer 14: inner protective
layer 20: first sensing electrode 23: lower junction 24, 44: trace
portion 25, 45: pad electrode 30: insulating layer 40: second
sensing electrode 43: upper junction portion 50: protective layer
60: pad protection electrode
* * * * *